Bark-removing apparatus comprising rotor and stationary cage



June 3, 1952 Filed May 4, 1950 CLARK ET AL 2,599,090

J. R. BARK-REMOVING APPARATUS COMPRISING ROTOR AND STATIONARY CAGE I 3 Sheets-Sheet l INVENTOR Jamwfi-hzi 21 J bemrMAaamy BY am ,4 $4M ATTORNEYS J. R. CLARK ET AL June 1952 BARK-REMOVING APPARATUS COMPRISING 2,599,090

1 ROTOR AND STATIONARY CAGE Filed May 4, 1950 5 Sheets-Sheet 2 ATTORNEYS June .3, 1952 J. R. CLARK ETAL 2,599,090

A BARK-REMOVING APPARATUS COMPRISING ROTOR TIO F119; May 4, 1950 3 Sheets- Sheet' 3 IIIIIIIIIIIIIIIIIIII/ and mounted for rotation about its axis.

Patented June 3, 1,952

BARK-REMOVING APPARATUS COMPRISING ROTOR AND. STATIONARY CAGE James R. Clark, Mobile, and Spencer M. Adams,

C oden,'Al-a. y.

Application May 4, 1950, Serial N o 160,050

7. Claims. (01. 144-408) This invention relates to apparatus for removing bark from logs and particularly for removal of bark from relatively short 10g sections whereby the woody material may be employed in the production of pulp without being contaminated by the bark of the trees.

Prior art devices for this purpose consist generally of a cylindrical d-rum arranged horizontally The drums conventionally comprise a roughened inner cylindrical surface to engage and abrade the bark from logs therein. In operation the prior art devices are loaded with a charge of logs and rotated by suitable power means. In these prior artdevices it is important that the cylinder not be completely filled with logs and that it not be rotated at very high speeds. If rotated at high speeds, centrifugal force acts to distribute the logs therein around the outer periphery of the enclosed space where they tend to move as a unit with the cylinder and without relative motion. Under such circumstances, no bark is removed from the logs. If the prior art devices are completely filled with a charge of logs there will likewise be no appreciable relative movement between the logs of the mass or the logs and the cylinder with a resultant failure of bark removal.

The present invention comprises generally a stationary cylindrical cage structure rigidly mounted on a suitable base and held against rotation. The cylinder is provided with a, rough inner surface and a rotatable rotor is mounted within the cage having radial arms dividing the interior space into peripherally open compartments, each of which is adapted to receive a charge of logs to be barked. Upon rotation of the rotor the logs are forced to move around the inner periphery of the cage and even though each compartment is filled to capacity such relative movement is enforced. The rotor may be rotated at relatively high speeds without the danger of the logs assuming a solid mass characteristic and in which the logs will be thrown against the cage surface and each other and forceably moved thereover to produce the abrading necessary for bark removal. g

It is therefore an object of this invention to provide a bark removing apparatus capable of being operated efficiently at relatively high speeds. e m

It is a further object of this invention to provide a bark removing apparatus simple in construction, yet rugged and durable. g M

It is a still further object of this invention'to provide a bark removing apparatus extremely easy and simple to load and unload.

Another object of this invention is to provide a bark removing apparatus having an outer drum or cage non-rotatably supported on a frame.

It is another object of this invention to provide such an apparatus in which the mingling and abrading action is performed on a plurality of small individual groups of logs for more efficient and speedy results.

It is still another object of this invention to provide such an apparatus constituting an improvement over prior art devices.

Still further objects and advantages of the invention will become apparent as the description proceeds with reference to the accompanying drawings wherein:

Fig. l is a side elevational view of. one embodiment of bark removing apparatus constructed in accordance with the present invention.

Fig. 2 is a sectional view taken substantially along the line 22 of Fig. l and showing the charging and unloading doors in full line in closed position and in open position by dotted line.

Fig. 3 is a vertical longitudinal sectional view taken substantially on line 3-3 of Fig. 2 but showing the central shaft in elevation.

The illustrated embodiment of the invention comprises merely one possible embodiment and is shown by way of example only.

According to theillustrated example, the device comprises a pair of longitudinal frame or runner members I which may be of wood or the like arranged in parallel spaced relation. As shown in the drawings the runners l are bevelled as at 2 to facilitate movement from plac to place, in the nature of a runner or skid. Extending transversely of the frame members I, and preferably adjacent opposite ends thereof, are angle iron frame members 3 which may be bolted or otherwise rigidly attached to the runners I. To each frame member 3 a pair of upstanding supports 4 is welded. The supports 4 are attached to the frame members 3 adjacent the ends thereof and extend upwardly and inwardly to upper frame elements 5. The frame elements 5 likewise may consist of suitably. cut angle iron sections and are welded to the supports 4 with an upper flange extending horizontally to provide substantially coplanar upper surfaces. Pillow bearing blocks 6 are bolted or otherwise attached to the coplanar surfaces of the fram elements 5 and are provided with aligned bearing openings. A pair of solid, circular, spaced end plates 1 is arranged withone plate rigidly attached to the frame members at each end of the apparatus, as by welding or the like, and each is provided with a central opening 8 in alignment with the other 3 and with the axis defined by the openings in bearing blocks 6. The end plates 1 are thus held permanently stationary and in parallel spaced relationship.

To the inner faces of the plate 1 and adjacent the peripheries thereof rings or bands 9 are welded to define axially extending flanges at the periphery of the plates 1. A plurality of spaced rings or bands In of the same proportions and diameter as the rings 9 are arranged in parallel concentric relationship and spaced substantially equal distances apart between the end plates. I:

and rings 9..

Extending between adjacent rings 9 and I and adjacent pairs of rings I 0 are a plurality of cage members II. Each member II is preferably formed of metal sections of channel shape in transverse section. The length and configuration of the members II is so chosen that they may be arranged to extend obliquely between ad- .jacent rings 9 and I0 to the inner surfaces of pair of rings are directed obliquely in the opposite sense. All of the members II are welded at their ends to the rings 9 or I and since the members between each pair of rings extend generally helically about the cage, the resultant arrangement of the inwardly directed ribs or flanges defines what is commonly known as a "herringbone pattern. As shown, the members II are spaced apart whereby all the inwardly directed flanges or ribs are substantially equally spaced throughout the inner periphery of the cage. The members I I, being welded to the rings In and the rings .9, define a single rigid cylindrical structure capable of maintaining its shape without additional supportand capable of withstanding large operational stresses.

The members H may be so curved or warped that the free edges of the inwardly directed flanges thereof define a truly cylindrical surface but they are preferably straight so that the mid portion of each of the members II is somewhat nearer the axis of the cylinder than the end portions thereof. By this arrangement the inner surface of the cage is not truly cylindrical but. includes longitudinal undulations in addition to the circumferentially spaced projecting rib portions. This construction insures more efficient contact with the surfaces of the logs being barked since the logs themselves are not truly cylindrical but are of irregular shape.

The rings II are not. integrally continuous throughout the periphery of the cage but are interrupted on opposite sides and short. arcuatev ring sections I2 and I3 are interposed between the ends thereof. The arcuate sections I2 and. I3 are of the same sectional shape and size as the rings. I 0 and comprise removable continuations All of thereof. The channel-shaped members II ex-- I define the complete cylindrical cage. The panels supported by the sections I2 and I3 constitute doors for the admission and discharge of logs from the apparatus.

Each of the rings. 9 and Ill is provided with a pair of outwardly directed bracket members I4 welded thereto and extending to the edges of the doors described. A pair of such brackets is provided on eachring adjacent each edge of each door. The lowermost portions of the rings Ill are further provided with a longitudinally extending brace member I5 which may be welded thereto'and provided. with reinforcing brackets t6. The sections I2 and I3 are provided with single bracket plates I 1 adjacent each longitudinal edge of each door so directed as to extend between the adjacent ends of an adjacent pair of brackets H1. The brackets I4 and I1 have aligned openings through their overlapped ends adapted to receive pivot. or looking rods I8 and I9. It willbe readily apparent that upon removal of either rod I9 the selected door may be. pivoted about the axis of its rod It to the positions illustrated in dotted line in Fig. 2 of the drawings. If desired, each door and the edge of the cage adjacent each doorway may have longitudinally extending reinforcing strips 20 welded thereto.

As clearly shown in Figs. 1' and 2 the tWo doors described are located on opposite sides of the cylinder and extended the full length thereof. The door shown, on the righthand side of Fig. 2 is located above the cylindrical axis While that on. the left'side of the figure extends considerably below the, cylinder axis to a position relatively close to the bottom of the cage. The purpose for this arrangement will become apparent later.

A central shaft consisting of a tube or pipe 22 is provided with end plugs, or trunnions 23 and 24 extending into the bearing blocks 6 to thereby support the shaft 22 for rotation. Inwardly of the end plates 1 of the cage, solid end plates 26 are welded or otherwise rigidly attached to the shaft 22. The end plates 26. of the rotor are circular and of a diameter slightly less than the inside diameter of the cage previously described. At equally spaced intervals along the shaft. 22 smaller circular plates 28 are mounted and rigidly attached to theshaft as by welding. Each plate 23 is provided with a plurality of radiallyextending arms 30 fixed thereto. The arms 30. on adjacent plates 28 are axially aligned so that their corresponding edges define a single longitudinal plane. Suitable. brace arms 32 may be arranged in overlapping relationship to the arms 30 in a manner clearly shown in Figure 2 and welded thereto to provide circumferential reinforcement for the arms, 30. The rotor structime may also be. provid d with longitudinally extending braces 34 and 3.6 welded to the arms on each of the plates 28 to add further rigidity to therotor.

The arms 30 extend outwardly to a position aligned with the outerperipheryof the end plates 26 slightly inwardly of the free edges of the inwardly directed flanges of channel members II of the cage.

The plug ortrunnion 24 extending from one end of shaft 22 has mounted thereon a suitable pulley 40' and; may be provided with a suitable brake and/or clutch mechanism; 42;. Any suitable source of power, such as Q; .6. .4.. (see; Fig. 1) may be, pr vided and ma e; supp r ed y u bra k t structure as. shown. a .6 to p ovide po er or operating the mechanism. A pulley 48 of the of the present invention. Clearly, any'suitable source of power may be connected to the rotor" in any desired manner and controlled by other means than those shown.

To operate the apparatus of the present invention, the rotor, if running, is brought to a stand-- still and the loading door above the axis of the cylinder is opened after removing pin or rod I9, thereby providing access to the interior of the cage and the compartments defined by aligned arms 30 of the rotor. Logs of a length substantially equal to the space between plates 25 may 6 We claim: 1. In a device of the character described, a stationary, substantially cylindrical cage arranged with its axis extending horizontally, a rotor mounted for rotation coaxially within said cage, said rotor comprising a plurality of. radially extending arms defining circumferentially spaced compartments for the reception of logs to be then be introduced into the apparatus and each compartment may be separately filled by intz'a'rmittently rotating the rotor to position the compartments successively at the loading door. After the apparatus is completely loaded, the loading door may be closed and pin 19 reinserted through the aligned openings in brackets l4 and to thereby lock the door in closed position. The apparatus is then ready for operation which consists merely in applying power to the rotor to rotate the same at the desired speed. As the rotor rotates it carries the charge of logs with it around the inside of the cage where the inwardly directed flanges or ribs of members ll engage the bark and remove the same from the logs. Engagement of the ribs with the bark of the logs tends to impede movement of the logs, thus inducing rotation of each log about its own axis and thereby producing additional rubbing r abrading action between the logs of the charge. Customarily, logs being treated are water-soaked and kept wet during this process. If desired, a stream of water may be directed onto the apparatus where it may enter the spaces between members II to keep the charge fully soaked during the barking operation. During operation of the apparatus in the manner described the rotor will be rotated in a clockwise direction as viewed in Fig. 2.

Apparatus according to the present invention has been constructed and operated whereby a complete charge of logs was loaded, peeled completely clear of bark, and unloaded in less than five minutes. The machine constructed averaged one cord of pine pulp wood every minutes, peeled clean, down through the inner bark.

After the peeling cycle has been completed, it is not necessary to stop the rotor to unload the charge. The pin I9 may be removed from the lower or unloading door, while the machine is in operation, and swung to the open position" shown in dotted lines in Fig. 2. It will be apparent that continued rotation of the rotor with the unloading door open results in the logs therein being projected outwardly and the compartments unloaded in sequence during a single revolution of the rotor. It has been found that the unloading operation results in the peeled log being thrown several feet from the apparatus and' thereby keeping the space around the apparatus clear.

Although a single specific embodiment of the invention has been shown and described herein, it is to be understood that many modifications may be resorted to within the scope of the invention, which is to be limited only by the appended claims.

barked, said arms extending outwardly closely adjacent the inner surface of said cage, a pair of doors providing access to the interior of said cage through the cylindrical wall thereof, one of said doors being located above said axis and the other door being located below said axis.

2. A device as defined in claim 1 wherein said doors extend the full length of said cage.

3. In a device of the character described, a stationary, substantially cylindrical cage comprising, axially spaced circular bands defining the cylindrical surface, a plurality of channelshaped members, each said member being attached at its ends to adjacent bands and arranged with said channels facing inwardly of said cylinder, a rotor in said cage mounted for rotation about the axis of said cylinder, said rotor having radial arms to engage and move logs about said axis.

4. A device as defined in claim 3 wherein said channel-shaped members between adjacent pairs of rings extend in opposite oblique directions whereby to define a herringbone pattern of ribs within said cylinder.

5. A device as defined in claim 4 wherein the innermost edges of said ribs define straight lines.

6. A device as defined in claim 3 including end plates defining end walls for said cylinder.

7. In a device of the character described, a stationary, substantially cylindrical cage having opposed ends, a rotor mounted for rotation coaxially within said cage, said rotor comprising a plurality of radially extending arms defining circumferentially spaced compartments for the reception of logs to be barked, said arms extending outwardly closely adjacent the inner surface of said cage, said rotor further comprising a rotatable shaft extending axially of said cylindrical cage, axially spaced flanges on said shaft, a plurality of said arms being attached to each flange and the arms on adjacent flanges being axially aligned in longitudinal rows, circular end plates on said shaft adjacent the ends of said cylindrical cage and defining with said arms a plurality of closed-ended spaced compartments on said rotor.

- JAMES R. CLARK.

SPENCER M. ADAMS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Ser. No. 354,762, Holzhey et al. (A. P. 0,), published May 11, 1943.

circumferentially 

